The invention relates generally to insulated concrete sandwich walls and methods of constructing such walls and, more particularly, to a two-piece connector that spans the insulation layer and engages a tie rod that passes through the insulation layer into the concrete layers on either side of the sandwiched insulation layer.
Insulated concrete sandwich walls are well known in the art. Typically, a concrete sandwich wall panel is created by installing a layer of insulating material between two layers of concrete. In order to create a safe assembly capable of resisting handling and service imposed forces, the insulation layer must be penetrated by a connection system that ties the two layers of concrete together.
Insulated concrete sandwich walls typically are constructed as horizontally-cast or vertically-cast assemblies. In both assemblies, the sandwich comprises an exterior concrete layer, an interior concrete layer, and an insulation layer that separates the concrete layers. Also in both assembly types, a plurality of connecting elements pass through the insulation layer and serve to tie the two concrete layers together after the concrete has hardened.
In vertically-cast assemblies, the individual concrete layers of the sandwich are cast between a pair of parallel, vertical forms. These forms may be located at the site of the to-be-completed building (site cast construction), or they may be located at an off-site location and used to cast a part of a building module that will be moved to the building site (modular construction).
In the present art of vertically-cast insulated concrete sandwich walls, the initial fabrication sequence typically begins with the erection of one of the pair of the concrete forms that will form one of the surfaces of the concrete wall being constructed. A grid of reinforcing steel for the first of the concrete layers is positioned adjacent to the forming surface of the concrete form.
A plurality of the through-insulation connectors are installed in the insulation layer and the insulation layer is positioned adjacent the reinforcing steel and parallel to the forming surface. Known systems call for the installation of the through-insulation connectors into a free-standing sheet or board of foam insulation prior to its positioning adjacent the first reinforcing grid. Most through-insulation connectors are comprised of two interlocking pieces that must be assembled from either side of the sheet of foam insulation at the same time. The insulation layer is most commonly of a size, for example, four feet by eight feet, to make it difficult for a single operator to reach from the edge of the insulation layer to position and interlock the two pieces of the connectors.
Since portions of the through-insulation connectors project laterally from both opposing surfaces of the insulation layer, the plurality of projecting elements must be threaded through the grid of the reinforcing steel. A difficulty in this step is that one of the projecting ties may impinge on a portion of the grid and be directed or displaced off-center. If a nearby tie also contacts a portion of the grid and is directed or displaced off-center in a different direction, the insulation layer will bind and may require manipulation of one or more of the projecting ties in order to move the insulation layer into place. The reinforcing steel grid for the other concrete layer is next positioned adjacent the opposite side of insulation layer and, again, the projections on the opposite side of the insulation layer must be threaded through the second reinforcing steel grid. The second of the pair of concrete forms is put into place, and concrete is poured on either side of the insulation layer. The through-insulation connectors include flanges or other structure which will engage and hold the insulation layer in position during pouring of the plastic concrete.
There is, accordingly, a need for a through-insulation connector assembly which would not only make it easier to assemble the connectors during construction of the wall, but also simplify the construction process. Such a connector assembly would enable a vertically-cast insulated concrete sandwich wall to be constructed in less time, with less labor and with the possibility of reducing the number of operators required to construct the wall.